Numerical indicator tube with built-in translating circuit

ABSTRACT

A numerical indicator tube which includes means for translating coded electrical information such as binary data into decimal readout.

United States Patent [72] Inventor Harold J. Rayner Wellesley, Mass.[21] Appl. No. 795,856 22] Filed Feb. 3, 1969 [45] Patented May 18, 1971[73] Assignee Raytheon Company Lexington, Mass.

[54] NUMERICAL INDICATOR TUBE WITH BUILT-IN TRANSLATING CIRCUIT 3Claims, 9 Drawing Figs.

[52] US. Cl 315/84.6, 313/1095, 315/52, 315/71 [51] Int. Cl ..H01j17/34, I-lO3k 23/38 [50] Field ofSearch 313/1095, 210; 315/846, 169, 51,52, 58, 71, 73; 340/324 [56] References Cited I UNITED STATES PATENTS3,250,938 5/1966 Frouws et a]. 313/1095 3,280,359 10/1966 Maloney et a1.313/1095 3,315,248 4/1967 Benn et a1 340/324 Primary Examiner-Roy LakeAssistant Examiner-E, R. La Roche AttorneysI-Iarold A. Murphy and JosephD. Pannone ABSTRACT: A numerical indicator tube which includes means fortranslating coded electrical information such as binary data intodecimal readout.

go eiogoge Ali/WWW I 9292 Patented May 18, 1971 3 Sheets-Sheet 2 w 0 m 3NR EE 2 4 6 6 ll v w w 4 w W x W H w 5 H I H l l l l -h ll J I- m M F m/u m H L II a a 8 8 w w o 2 3 Sheets-Sheet 3 Patented a 18, 1971 4 7 a 9f 4 7 8'2: l BINARY T0 DECIMAL I DECODER-DRIVER L INVENTORS mfiaw J.RAYNER l uT l COMPUTER BINARY TO DECIMAL DECODER-DRIVER COMPUTER INPUTPRIOR ART NUMERICAL tunic/iron TUBE wmi BUILT-IN TRANSLATING CIRCUITBACKGROUND OF THE INVENTION A numerical -indicator tube is a gaseousglow discharge device comprising a transparent envelope containing ananode electrode, at least one cathode glow electrode, and a gas suitablefor supporting cathode glow. When a suitable electrical potential isapplied between the anode and a cathode electrode, the cathode glows andspace current flows through the gas between the cathode and the anode.

Usually there are provided a plurality of cathode electrodes ofdifferent shapes such as, for example, numerals, letters, and/or otherselected characters to be illuminated one at a time, the cathodeelectrodes being connected to separate terminal pins extending throughthe base of the envelope.

Tubes of this type are particularly suited for use with circuits whichutilize binary principles of operation. Binary counters, for example,which use a series of interconnected flipflop circuits are one example.Such decade counters generally employ a matrix for translating a signalrepresenting a binary number to a signal representing a decimal or othernumber or character equivalent of the binary number. Such equivalentnumber or character is displayed as a direct readout of a count made bythe counting circuit. In another example, computer information istransmitted to a decoder-driver which translates the information into adecimal equivalent which is then visibly displayed by the tube.

From the foregoing, it will be apparent that associated translatingcircuitry is required for connection to the tube so that the tube may beoperated. Such circuitry may be in the form of a number of separateelectronic components wired together and connected to the tube, or inthe form of a module containing miniaturized components such as anintegrated circuit which accomplishes the same objective. Such circuitsmay be relatively complicated as in the translation of binaryinformation from a computer, for example, into equivalent decimalsignals, and often comprise bulky packages which are connected to a tubesocket by a number of leads or wires.

Any thoughts of incorporating semiconductors into a gasfilled electrondischarge device have been generally discarded because electron tubesgenerate considerable heat during their operation, and such heat hasbeen known to be sufficient to cause degeneration or destruction of thesemiconductors, and thus would render the tube useless.

SUMMARY OF THE INVENTION The present invention improves upon theabove-described prior art by the provision of a numerical glow dischargeindicator tube which contains, as a component part thereof, anintegrated circuit signal translating means which is mounted internallyof the tube and connected to selected terminal pins for externalconnection through a socket and lead wires to a computer output or thelike, and which is also connected internally of the tube directly torespective cathode electrodes for operation thereof in response tobinary or other information transmitted to the tube through circuitryassociated with external devices.

Thus, there is achieved a novel, compact tube structure which itselfembodies control circuitry such as signal translating devices whichpreviously comprised bulky electronic components located external to thetube and which required interconnection means to a tube socket forsuitable operation of the tube in a desired manner.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objectives ofthisinvention will become apparent from the following description takenin connection with the accompanying drawings, wherein;

FIG. 1 is a vertical sectional view of a tube embodying a preferred formof the invention with the electrode structures shown in elevation;

FIG. 2 is a side elevational view of the tube shown in FIG. I with theenvelope removed;

FIG. 3 is a rear elevational view of the tube shown in FIG. 1 with theenvelope removed;

FIG. 4 is an elevational view, greatly enlarged, of a cathode electrodeshowing its supporting means;

FIG. 5 is an enlarged elevational view of a cathode spacer;

FIG. 6 is a vertical sectional view through the translator utilized inthe tube of FIG. 1;

FIG. 7 is a plan view of the translator shown in FIG. 6 with the topplate removed;

FIG. 8 is a schematic representation of a conventional characterindicating glow discharge tube and associated external decoder-drivermeans; and

FIG. 9 is a schematic representation of the tube of FIG. 1 illustratingthe principles of this invention.

SUMMARY OF THE PREFERRED EMBODIMENTS Referring to the drawings whereinlike characters of reference designate like parts throughout the severalviews, the numerical indicator tube shown in FIGS. 1, 2 and 3 comprisesa glass envelope or bulb 10 which has been evacuated of air and filledwith an ionizable gas such as neon, argon, krypton, or the like at asuitable pressure, for example in the range of about 40-120 mm. Hg. Theenvelope includes a base portion or stem 12 through which metal basepins 14 extend and by means of which electrical connection is made tosuitable external electrical circuit elements. The upper or inner endsof the pins 14 terminate within the envelope adjacent a group of threetransversely disposed insulating discs 16, 18 and 20, preferably of micaor the like. Between the upper two discs 18 and 20 reposes the heads oftwo or more eyelets 22 which extend downwardly through the two lowerdiscs 16-18 and are mounted over and welded to the adjacent ends of acorresponding number of pins 14 for support of the discs 16-18 on thepins.

Resting upon the upper surface of the upper disc 20 is the lower end ofan anode 24 which comprises a solid sheet material portion 26, as seenbest in FIGS. 2 and 3, which extends across a portion of the envelope,and a mesh portion 28, as seen best in FIGS. 1 and 2, whichextendscircumferentially of the envelope from the sides of anode portion 26.Anode portion 26 is provided at its lower and with outwardly struckangle pieces 30 to which the mesh portion 28 is attached, and tabs 32extending down through slots in discs 20 and 18 and which are bent overto underlie disc 18. By this means, the upper disc 20 is held in placeagainst the heads of eyelets 22 and the anode 24 is firmly supported inposition of use.

Supported upon the top of anode 24 is another set of three transverselyextending insulating discs 34, 36 and 38. The adjacent end of the solidportion 26 of anode 24 is also provided with angle pieces 40 to whichthe upper end of mesh portion 28 is attached, and tabs 42 which extendthrough disc 34 and are bent to overlie the upper surface of the disc34. Eyelets 44 extend through discs 36 and 38 with their heads disposedbetween discs 34 and 36. Into the eyelets 44 project-headed stakes 46which extend downwardly through another insulating disc 48, the stakesbeing welded into the eyelets for holding disc 48 in position in spacedrelation with disc 38.

The tube, being a character indicator tube of the glow discharge type,includes a plurality of cathode electrodes 50 in the form of characterssuch as numerals, letters, symbols, or the like to be visibly displayed.While numerals are disclosed herein as being the form of the charactersutilized in the presently described tube, other characters may beutilized as is well known in the art.

Briefly, the cathode electrodes 50 of this disclosure are numerals, 10of such elements being provided, including the numerals 0" to 9" Forpurposes of simplicity, all of the cathode electrodes are not shown inthe drawings. These cathode electrodes 50 may be made of any suitablemetal, for example, stainless steel, aluminum, Nichrome, molybdenum, orthe like, and may be made in any suitable fashion as, for example, byetching, stamping, formed wire, or the like.

The cathode elements are shown as mounted in a transversely extendingstack and are oriented substantially parallel to each other and facingone of the sidewalls of the envelope for viewing therethrough andthrough the mesh or screen portion 28 of the anode electrode 24. As seenin FIG. 1, the numeral 6 is shown as being the foremost character in thestack of cathode elements, but the arrangement of the elements may be asdesired.

The cathodes are made of suitably shaped and sized material and aresuitably displaced laterally with respect to each other as is well knownso that each one is not obstructed by the others and each is clearlyvisible from the front or side of the tube as viewed in FIG. 1.

Although the tube electrodes as depicted are arranged to be viewedthrough a sidewall of the envelope in the embodiments described herein,it will become apparent from the following description that they may bearranged for viewing through the top of the envelope, if desired, andthis invention is utilizable in connection with any selected cathode andanode arrangementor configuration.

The cathodes 50 are supported at each end by the respective discs 34 andand, to accomplish this, each cathode 50 is provided with upper andlower slotted tabs 52 and 54 respectively (FIG. 4). The tabs 52-54 areslotted and are adapted to slidingly engage with slots provided thereforin the respective discs 34-20. The cathodes 50 may be spaced from oneanother by separate thin slotted dielectric spacers 56 (FIG. 5). Thetabs 52 and 54 are alternately stacked with spacers 56 so it will beapparent that the spacers also serve the function of preventing theglowing tabs from being observed during operation of the tube, whilepermitting the glowing numeral or character itself to be visible, as iswell known.

Each cathode 50 is provided with a suitable lead wire in the form of arelatively flat lead member 58 (FIG. 4) which extends from each uppertab 52 and which is suitably coated with magnesium oxide or the like toprevent glowing.

In accordance with this embodiment of the invention, the cathodes 50 arenot connected to terminals or pins 14 as in the prior art, but areconnected instead to a signal translator 60 which is preferably locatedbetween discs 38 and 48. The translator 60 may take any of many formsbut conveniently includes a cylindrical dielectric member of casing 62(FIGS. 6 and 7), for example glass, through which extend a multiplicityof flat, radially extending leads 64. The inner ends of leads 64 restupon a shelf 66 formed on the inner wall of the casing 62, and the outerendsproject outwardly from the casing to a substantial degree, as shown.Casing 62 is closed at the bottom by a plate 68 of metal, preferablygold-plated kovar or the like, which is sealed to the glass casing bysuitable glass-to-metal sealing means.

Fixed on the inner surface of the bottom plate 68 is a signaltranslatingcircuit 72 which may be a suitable integrated circuit designed to acceptbinary or other signal information and convert or translate it into asignal representing a decimal. Such integrated circuits may have anyselected configuration and will have pads or contact areas thereon, asis well known, to which one end of gold wire leads 74 are bonded. Theparticular translating circuit itself does not in itself constitute theinvention only insofar as a translating circuit comprises a part of thepresent inventive combination. Integrated circuits are old and wellknown and, in this invention, may be of a type which, for example,translate binary information from a computer into decimal signals, orwhich provide counting information to be indicated in the tube byvisible numerals or other characters.

The gold heads or wires 74 are connected by conventional welds or brazesat their other ends to the adjacent ends of respective leads 6.4 asshown in FIGS. 6 and 7. A top plate 76 of, for example, gold-platedkovar is bonded by means such as a gold-tin alloy ring 78 to kovar ring70 which forms a glassmetal seal to casing 20 to close the translatorunit.

It will be noted that several more leads 64 are provided than arerequired. This is to permit use of a device of this type with differentintegrated circuits having a greater or fewer number of outputconnections, if desired. The unused and unneeded leads 64 may be cut offat the exterior surface of casing 62.

In accordance with this invention, the translator 60 is connecteddirectly with the cathodes 50. To achieve this, the leads 64 are welded,brazed or otherwise connected to respective leads 58 extending from thecathodes 50. Leads 58 extend upwardly from the cathodes and, if desired,through disc 36, then are bent to extend radially to a point where theymay be made to contact and be sealed to the selected leads 64. Thisparticular method of connecting the leads 58 and 64 is exemplary only,since any other means is deemed to come within the scope of thisinvention.

In order to provide the translator 60 with the required inputinformation signals, selected input pads on the integrated circuitdevice 72 are connected by other wires 74 to leads 64, which leads 64are in turn connected by wires 80 to respective terminal pins 14. Theseparticular pins 14 are connected to the external signal providing meanssuch as a computer, for example.

In order to prevent shorting of wires 80 to each other or to other tubeelements, two sheets 82 and 84 of mica or other suitable insulatingmaterial are disposed against the rear surface of the solid portion 26of anode 24, and the wires 80 extend downwardly between these sheets,the sheets and wires being held in place by one or more wires 86 whichsupport the assembly upon the anode portion 26 as shown in FIG. 3.

In FIG. 3, a ground lead is indicated by still another wire 88 similarto wires 80 and which is connected to a selected terminal pin 14.

From the foregoing, it will be apparent that, when a suitable potentialis applied to the anode from its terminal pin, the translator shorts outa selected cathode to ground, causing it to glow. Anode potential isalways present and is not switched. When a computer, counter, or otherexternal source of information provides signals which are transmittedinto the tube through other selected terminal pins to the translatingunit 60, the unit will, in accordance with this invention, convert thesignals into decimal information signals which will switch a selectedcathode electrode 50 to ground potential, causing the proper energizingvoltage to appear between the selected cathode and the anode. This willcause the selected cathode to glow in the well-known manner.

While the translator 60 has been described above as being located nearthe top of the tube envelope between discs 38 and 48, it may be locatedelsewhere except where it would interfere with the visibility of thecathode electrodes. It is necessary, however, to locate the translatorin a position where it will be unaffected by heat during tube processingsuch as occurs, for example, when the base or stem 12 is sealed to thebottom of the envelope 10.

Referring now to FIG. 8, the glow discharge tube 90 is provided with ananode and ten cathode electrodes. In this diagrammatic example, abinary-to-decimal decoder-driver 92 external of the tube is connected byten separate leads to 10 terminal pins on the tube. Thus, the tube inthis illustration requires a total of ll terminal pins, and thedecoder-driver requires an additional six terminals in order to connectit into a computer. In FIG. 9, the decoder-driver is built into the tubestructure in accordance with this invention and accomplishes the samefunctions as the device of FIG. 8 with a total of only seven terminalpins projecting from the tube, four of which are connected directly tothe computer. The advantages of this are obvious.

In US. Pat. No. 2,906,906, there is shown and described a tube which isadapted to provide a multiple numeral readout achieved by providing twoor more stacks of numerals and wherein numerals in each stack may beenergized for simultaneous viewing. The present invention is alsoreadily adaptable for use in a tube of this type.

From the foregoing, it will be apparent that the objectives of thisinvention have been achieved by the novel structure shown and described.It is to be understood, however, that through the mesh portion, a pairof dielectric discs between the cathode stack and the end of theenvelope opposite the base, terminal means extending through said base,and semiconductor-type signal-translating means mounted between saiddiscs for converting a first information-carrying signal into a secondsignal containing a numerical representation of the informationcontained in said first signal, first leads connecting said terminalmeans to said signal-translating means for transmitting a first signalthereto, and second leads connecting said signal-translating means tothe cathodes for transmitting a second signal to a respective selectedcathode.

2. The tube defined in claim 1 wherein said signal-translating meanscomprises a dielectric enclosure, a semiconductor device within saidenclosure, first conductors extending through the enclosure connected tosaid first leads at one end and to the semiconductor device at the otherend, and second conductors extending through the enclosure connected tothe semiconductor device at one end and to said second leads at theother end.

3. The tube defined in claim 2 wherein said semiconductor device is anintegrated circuit.

1. A gaseous glow discharge tube comprising a transparent dielectricenvelope including a base, a stack of indicator cathodes mounted on thebase and adapted to glow and to be visibly observable through theenvelope, an anode mounted on the base and surrounding the cathodes andcomprising a mesh portion and a solid portion, the cathodes beingviewable through the mesh portion, a pair of dielectric discs betweenthe cathode stack and the end of the envelope opposite the base,terminal means extending through said base, and semiconductor-typesignaltranslating means mounted between said discs for converting afirst information-carrying signal into a second signal containing anumerical representation of the information contained in said firstsignal, first leads connecting said terminal means to saidsignal-translating means for transmitting a first signal thereto, andsecond leads connecting said signal-translating means to the cathodesfor transmitting a second signal to a respective selected cathode. 2.The tube defined in claim 1 wherein said signal-translating meanscomprises a dielectric enclosure, a semiconductor device within saidenclosure, first conductors extending through the enclosure connected tosaid first leads at one end and to the semiconductor device at the otherend, and second conductors extending through the enclosure connected tothe semiconductor device at one end and to said second leads at theother end.
 3. The tube defined in claim 2 wherein said semiconductordevice is an integrated circuit.